Machine for testing bottles

ABSTRACT

Apparatus for testing bottles to determine whether they will withstand internal pressure as from a carbonated beverage, also for detecting flaws in crown of bottle which may result in leaks. Hydraulic pressure is applied internally by hydraulic fluid, usually water. Bottle is filled with low pressure water, then high pressure water is used to apply pressure. Bottle is held between a sealing chuck which contacts and seals crown and a bottom member bearing against bottom of bottle, thus simulating force applied to bottle during filling with beverage and capping. .[.Means are.]. .Iadd.A valve is .Iaddend.provided to remove air displaced during filling with low pressure water.

This invention relates to apparatus for testing beverage bottles todetermine whether they will withstand internal pressure with an adequatedegree of safety.

Several different approaches have been provided or suggested to theproblem of testing beverage bottles, for example, soft drink beveragebottles, both those which are carbonated and therefore generate aconsiderable internal pressure and those which are uncarbonated. Thepurpose of such testing is to determine whether the bottles areadequately strong to resist internal pressure.

One approach is to apply mechanical pressure to the exterior of thebottle. However, it is not possible to apply a uniform pressure to theentire exterior of a bottle, and it does not simulate the internalpressure applied to a bottle which has been filled with product andcapped. Furthermore, this approach is not well adapted to reveal thepresence of defects in the crown of the bottle which may cause leaks.

Another approach has been to apply pneumatic pressure to the interior ofa bottle, but such approach is disadvantageous because when bottles failthey do so with explosive effect. The resulting shattering is hazardousto personnel and is likely to inject pieces of glass into machinery.

It is believed that the best approach to testing bottles is to fill themwith the test liquid, for example water, and to apply hydraulic pressureto the filled container. This has the advantage that, if a bottle failsit does not shatter and scatter pieces of glass. With internal hydraulicpressure testing, when a bottle fails it does not do so with explosiveeffect. Also, it simulates the pressure to which a bottle is subjectedwhen it is filled with product and capped.

In internal hydraulic testing one approach has been to fill bottles in acompartment where a liquid, usually water, is showered over a large areaand fills the bottles. This, however, requires the handling of aconsiderable quantity of water and for that reason is disadvantageous.

U.S. Pat. No. 3,826,126 describes an operation which is advantageous,namely filling each bottle in turn with low pressure water and then,when the bottle is full, introducing into the bottle water at a highpressure for the purpose of testing. However, the procedure of thatpatent is disadvantageous because it suspends a bottle during testing,therefore does not simulate the forces applied to a bottle duringfilling with product and capping; also the apparatus does not provide asgood a seal while filling and testing as is desirable. Further, it isnecessary during filling with low pressure water to leave clearancebetween the sealing chuck and the crown of the bottle for air to escape.

It is an object of the present invention to provide bottle testingapparatus employing the concept of internal hydraulic testing andemploying also a cycle in which the bottle is filled first with lowpressure water and is then subjected to hydraulic pressure from a highpressure water supply, but in which speed of operation is enhanced. (Itwill be understood that other liquids may be used in place of water,which, however, is adequate for the purpose, inexpensive andnon-polluting.)

It is another object to provide a testing procedure which simulatesfilling of the bottle with product and capping.

It is a further object of the invention to provide hydraulic testingapparatus which maintains a seal on the bottle during low pressurefilling as well as high pressure testing.

Yet another object is to provide apparatus, which will detect leaks dueto faulty crowns.

The above and other objects of the invention will be apparent from theensuing description and the appended claims.

One embodiment of the invention is shown in the accompanying drawings inwhich:

FIG. 1 is a diagrammatic view of the apparatus including its pneumaticand hydraulic circuits;

FIG. 2 is a view on a larger scale than that of FIG. 1, being a verticalmid-section through a turret showing a single filling and testing headand hydraulic and pneumatic connections to sources of air underpressure, water under low pressure and water at high pressure andshowing also bottles of two different sizes and adjustments means toaccommodate the different sizes;

FIG. 3 is a vertical mid-section through the testing head shown in FIG.2, the air cylinder operating mechanism of FIG. 2 being shown onlyfragmentarily, the filling spout or quill being shown in the up positionbefore it is inserted into a bottle;

FIG. 4 is a view similar to that of FIG. 3 but showing the quill in itsdown position within a filled bottle, showing the sealing chuck inengagement with the crown of the bottle and showing the positions ofpertinent parts while hydraulic pressure is applied;

FIG. 5 is a section taken along the line 5--5 of FIG. 3 showing themanner in which the sealing chuck is mounted;

FIG. 6 is a fragmentary top plan view of the turret plates showing themanner in which the pockets in the turret are adjusted for bottles ofdifferent diameters (in this instance a small diameter); and

FIG. 7 is a view similar to that of FIG. 6 but showing the turret platesin adjusted position for bottles of larger diameter.

Referring now to FIG. 1, this is a diagrammatic view showing thehydraulic and pneumatic circuits and showing the apparatus of a singletesting head or station. It will be understood, and it will be morefully apparent from the description hereinbelow with reference to FIG. 2that the present invention contemplates providing a rotary turret withpockets to receive bottles in succession from a bottle entry conveyorand to rotate them through a testing station into an exit bottleconveyor to the next unit, for example, a washer to wash the bottlesbefore they are transported to a filling machine and thence to a cappingmachine. Such inlet and outlet conveyors (not shown) may be ofconventional type, e.g. screw conveyors. However, the invention may beemployed with suitable modification for an in-line system in which thereis a single testing head in line with the progression of bottles from aninput point to an output point. However, it is preferred to use a rotaryturret as described and illustrated hereinbelow.

Sufficient time is preferably allowed between the testing step and thewashing step so that the water used for testing and still in the bottlewill soak the interior of the bottle and facilitate washing. This is ofimportance in the processing of used returnable bottles.

The apparatus is generally designated by the reference numeral 10. Abottle 11 is shown having the usual tapered neck 12 and rolled rim orcrown 13. A filling and pressure testing head or unit 14 is shown havinga tube or quill 15 which is to be inserted into the bottle for thepurpose of filling with low pressure water. A sensing unit 16 having arod 17 is provided, the function and purpose of which are to sensewhether a bottle has failed or has a leak and, if so, to energize adevice (which is well known in the art and requires no descriptionherein) which removes the bottle that has failed or has evidenced aleak.

A pneumatic operating and control unit 18 is provided including acylinder 19, a rod 20 and a piston 21 which is reciprocable within thecylinder 19. Air supply line 30 (see the upper right portion of FIG. 1)connects a source of air under pressure (not shown) e.g. 80 p.s.i. gaugeto a rotary valve 31 which opens and closes connection between the inletline 30 and outlet line 32 in timed relation to rotation of the turret140 (see FIG. 2) to provide air under pressure when and as needed and toshut off communication of air pressure when desired. Line 32 connects toa pressure reducing valve 33 of known construction and air at reducedpressure (e.g. 20 p.s.i. guage) passes through a line 34 to the lowerend of cylinder 19 such that it acts to lift the piston 21.

A branch 35 in line 32 upstream from the pressure reducing valve 33connects to a three-way valve 36 having an exhaust port 37 and a port 38which connects to a line 39 to the upper end of cylinder 19 above thepiston 21. It will be seen that relatively low pressure air is deliveredto the bottom of cylinder 19 beneath the piston 21 and that relativelyhigh pressure air is delivered to the top of cylinder 19 above thepiston 21, such being carried out in the proper sequence as describedhereinbelow. Valve operating means is provided in the form of astationary cam 40 fixed to the frame of the machine which in contactedby a cam follower roller 41 which is rotatably mounted on a rod 42, themovement and position of which determine whether high pressure air isdelivered through line 35, valve 36 and line 39 to the upper end ofcylinder 19.

The low pressure water circuit will now be described. A line 50connected to a source of low pressure water, for example, water at 45p.s.i.g., connects through the inlet 51 of the stationary portion 52 ofa rotary valve 53, the rotary portion being indicated by the referencenumeral 53a. The rotary member 53a is formed at intervals with outletports 54 which connect through a line 55 to a check valve 56 having aball 57 which seats against a seat 57a. The outlet 58 of the check valve56 connects by a line 59 to filling and testing unit 14.

The high pressure water circuit will now be described. It comprises aline 60 connected to a high pressure source of water, for example, 150p.s.i.g. and is in turn connected by the rotary valve 31 to a line 61.Line 61 is connected to a valve 62 having an outlet port 63 which isopened and closed by cam means including a stationary cam 64 fixed tothe frame of the machine, a cam follower roller 65 and a rod 66. At theappropriate time the valve 62 is operated to connect the high pressurewater supply line 61 with the port 63 whereby high pressure water isdelivered through line 67 to a check valve 68 having a ball 69 seatingagainst the seat 69a and having outlet port 69b. Line 70 connects theoutlet of check valve 68 with the inlet port 71 of an air bleed orshuttle valve 72. The valve 72 has, besides the inlet port 71, outletports 73 and 74, a valve seat 75 for a ball 76, another seat 77 for theball 76 and a spring 78 which normally acts to cause the ball 76 toassume the position shown in FIG. 1, i.e. closing port 71 and openingport 74. The port 73 is connected by a line 79 to the filling andtesting unit 14.

Referring now to FIG. 2, wherein identical reference numerals identifythe same parts as in FIG. 1, as will be seen many of the connectinglines are of flexible material to accommodate themselves to up and downmovement of the testing head 14 and the pneumatic unit 18.

Referring now to FIG. 3, the interior construction of the filling andtesting head 14 is there shown in detail. As will be seen, the head 14comprises, as its main structural element, a cylinder 89 formed with acentral cylindrical cavity 90 formed with a bottom shoulder 91 and anextension 92 of smaller diameter than the cavity 90. A washer 93 isseated on the shoulder 91. Within the cavity 90 there is a piston 94which reciprocates within the cavity 90, its upward movement beinglimited by a ring 95 held in place by lock ring 96. The lower end ofpiston rod 20 is threaded into the piston 94. An O-ring 98 seated in anannular groove 99 in the piston 94 serves to seal the piston against thewalls of the cavity 90. At its lower end the piston 94 is formed with acavity 110 to receive a spring 112 which is confined between the washer93 and the upper end of the cavity 110. The cavity 110 has an extension110a of a smaller diameter which has a radial opening 111 which isintended to communicate at the proper moment with low pressure waterline 59. A pad 112a secured to the lower end of piston 94 serves as aseal.

The sensor 16 comprises a body portion 120 threaded into the body 89 andformed with a passageway 122 which enlarges into a chamber 123 thusproviding a shoulder 124. An O-ring 125 is provided as a seal to preventoutflow of fluid. A spring 125 confined between a collar 126 on the rod17 and a washer 127 held in place by a lock ring 128 normally urges therod 17 and its inner extension to the right as viewed in FIG. 3 so thatthe tip of the extension normally projects into an annular cavity orpassage 130 surrounding the quill 15. The quill 15, as will be seen, isformed with a passage 15a.

The high pressure water line 79 is threaded into the body 89 andcommunicates with a radial passage 135 which in turn communicates withthe annular passage 130.

A sealing chuck 140 is shown which is of rubber or resilient plasticconstruction and is sufficiently resilient so that under pressure itwill seal firmly against the crown 13 of a bottle as shown in FIG. 4.The chuck 140 fits into a socket 141 at the lower end of the body 89.The wall of socket 141 is formed with slot 142 to receive a clip 143which serves to hold the chuck in place but which (see FIG. 5) can bepulled out and detached for replacement of the chuck. The chuck 140 hasa stepped interior configuration including a cylindrical mid-portion146, a tapered, frusto-conical top portion 147 which seats firmlyagainst the crown of a bottle as shown in FIG. 4 and a flaring bottomportion 148. The frusto-conical portion 147 is tangent to the outer partof the crown 13 of the bottle 11 such that it adjusts to small, normalvariations in the shape of the crown. By this means the seal between thechuck 140 and the crown 13 simulates the seal between the cap and crownof the bottle when filled with product.

Referring again to FIG. 2, the turret which carries the several units 14and 18 is generally designated by the reference numeral 150 and itcomprises plates 151 welded to the main turret shaft 152 which isjournalled in the frame 153 of the machine. To support each bottle inone of the testing units a plate 154 is provided which is part of anangle piece 154a welded or otherwise suitably connected to the framemembers of the turret and upon which a bottle 11 is seated to be held inproper alignment with the quill 15. Plates of double thickness 155 and155a are provided which cup the bottle on the inward side. Rails 157held by brackets 158 confine the bottle on the outer side. The plates155 and 155a are secured together by means of screws 161 and slots 162.As will be seen by reference to FIGS. 6 and 7, by loosening the screws161 and rotating the upper plates, the pockets 163 which receive thebottles may be adjusted in size to accommodate bottles of smallerdiameter (FIG. 6) or larger diameter (FIG. 7). When adjustment has beenmade, the screws 161 are tightened.

Also shown in FIG. 2 is height adjustment means comprising a bracket 170secured to the frame of the machine on which an angle bracket 171 ismounted by a screw 172 in an elongated vertical slot (not shown) Byloosening the screw 172, the bracket 171 may be moved up or down, forexample, between the position shown in FIG. 2 for tall bottles and alower position (not shown) for short bottles. The cap 173 on the rod 20contacts the bracket in its up position (which is determined by theheight of the bracket 171) thereby limiting upward travel of the rod 20.By this means, the travel is adjusted for a large bottle or a smallbottle.

The rod 17 of sensor 16 is intended, when a bottle holds pressureproperly, to contact a micro switch 180 which requires height adjustmentfor bottles of different heights. This is accomplished by mounting themicro switch 180 on a bracket 181 which is connected by a screw 182 to aslot 183 on a post 184, which permits height adjustment.

In operation, the apparatus functions as follows:

An infeed such as a well known type of screw feed (not shown) feeds thebottles in timed relation to rotation of the main turret shaft 152, suchthat each bottle in turn is deposited in a pocket 163 in the turret.Referring to FIG. 1, as each bottle in a pocket reaches a certain point,cam 40 acts on roller 41 to connect high pressure air line 35 to line 39and thereby to cause piston 21 to undergo a down stroke together withthe body 89 of head 14 and the quill 15. Referring to FIG. 4, as thechuck 140 seats on the crown 13 of a bottle as shown in FIG. 4, furtherdownward movement of body 89 is arrested. Continued downward movement ofthe rod 20 acts to move piston 94 downwardly in cavity 90 against theforce of spring 112, which is compressed as shown in FIG. 4. At anappropriate time rotary valve 53 (see FIG. 1) connects low pressurewater line 50 with line 55 and through check valve 56 to line 59 andpassage 111 in piston 94, which at this time is in alignment with line59. Low pressure water therefore passes through passages 110a and 110 inthe quill 15 and thence into the bottle. As the bottle fills, air thatis displaced by the water vents through the annular space between quill15 and the neck of the bottle, passage 135, line 79 and port 74 inshuttle valve 72. This makes it possible to fill the bottle quickly withwater and the seal between the chuck 140 and the bottle is maintainedduring filling.

The timing is such that when the bottle is filled, cam 64 (see FIG. 1)acts on roller 65 to cause valve 62 to connect high pressure water fromline 61 to line 67 and thence through check valve 68 and line 70 toshuttle valve 72. The high pressure water causes ball 76 to unseat fromthe position shown in FIG. 1 and to seat on the bottom seat 77, therebyclosing port 74. High pressure water passes by way of line 79 to passage135 (see FIG. 4) and through annular space 130 and chuck 140. This highpressure acts on the inner end of rod 17 and pushes it to the outerposition shown in broken lines in FIG. 4. The rod therefore contactsmicro-switch 180 (see FIG. 2) which energizes (or de-energizes) acircuit to signal that pressure has held and that the bottle is sound.If a bottle fails, or if it has a flaw which causes leakage of water outof annular space 130, the resulting signal [i.e., retention of rod 17 inits inner (full line) position] indicates a faulty bottle. A pusher orother mechanism of known construction is then activated to eject thefaulty bottle. Suitable mechanisms and circuits for these functions arewell known and require no description herein.

After a suitable dwell of the piston 94 in the position shown in FIG. 4,the cams 40 and 64 act to shut off the supply of high pressure water tothe head 14 and of high pressure air to the top of cylinder 19,whereupon lower pressure air (which is always supplied to the bottom ofcylinder 19 through line 34) acts to raise piston 21 and with it head 14and to return piston 94 to the position shown in FIG. 3 in readiness foranother cycle.

Timing is accomplished by valves 31 and 53 and by cams 40 and 64. Valve53 is adjusted so that each bottle is slightly overfilled with water.Cam 64 is designed and/or adjusted so that high pressure water issupplied for a suitable period of time, e.g. 0.2 second in the case ofconventional 6 to 8 fluid ounce bottles and to hold the high pressurefor about 0.5 second. These dwell periods are, of course, subject tochange according to requirements.

The tube or quill 15 may be dispensed with and the chuck 140 may beformed with inner and outer passages, corresponding to passages 15a and130. However, a tube or quill which extends into a bottle and whichforms with the chuck an annular passage is preferred.

It will therefore be apparent that a new, useful and advantageousapparatus has been provided for testing bottles by internal hydraulicpressure.

We claim: .[.1. Apparatus for testing a bottle at a test station withwater under pressure to test the bottle for failure or for a leak, saidapparatus comprising: the pressure test..].
 2. A test apparatus forsupplying low pressure and high pressure water to a bottle to bepressure tested at a testing station said apparatus comprising:(a) atest head movable between a first retracted position separated from abottle at the test station and a second sealing position in sealingcontact with such bottle, said head having a sealing portion (b) a tubecarried by the test head and projecting from the sealing portion thereofto penetrate the bottle when the test head is in its second position,said tube providing a first, central passage for low pressure water intoa bottle and forming with the head a second.[., annular.]. passagebetween the test head and the tube for passage of high pressure waterinto the bottle, (c) said head being provided with a first duct forcommunicating said .[.annular.]. .Iadd.second .Iaddend.passage with asource of high pressure water (d) said head being also provided with asecond duct for communicating said tube with a source of low pressurewater (e) a valve member reciprocable within said head between a firstposition closing said second duct and a second position opening saidsecond duct and (f) means normally holding said valve in its firstposition but acting to move the valve to its second position when thebody is in sealing engagement with a bottle.
 3. The test apparatus ofclaim 2 wherein said valve member (e) is in the form of a pistonreciprocable within said head between a first position closing saidsecond duct and a second position exposing said duct, a spring withinthe head acting normally to hold said piston in its first position andyielding when the head makes sealing contact with a bottle and an axialforce is applied to move the piston to its second position.
 4. Pressuretesting apparatus for applying hydraulic pressure to the interior of abottle comprising:(a) means for holding a bottle upright at a teststation with its neck uppermost. (b) a test head mounted for verticalmovement between an up position retracted and separated from the bottleand a down position in sealing contact with a bottle at said station (c)said head having an axial passage and a tube within such passageprojecting beyond the lower end of the head such that it penetrates abottle at the test station when the head is in its down position and insealing engagement with the bottle, said tube and head forming anannular passage for flow of water into a bottle (d) means forautomatically moving said head in a repetitious cycle comprising a downmovement to seal against a bottle and to cause the tube to penetrate thebottle, a dwell during filling and testing and an up movement aftertesting has been completed to retract the head and tube from the bottle(e) means for automatically supplying low pressure water to said tube tofill the bottle during the first portion of the dwell part of the cycle(f) means for automatically supplying high pressure water to saidannular passage during a subsequent portion of the dwell part of thecycle to apply a test pressure to the bottle (g) means for terminatingflow of both low pressure and high pressure water before the end of thedwell part of the cycle and (h) means for automatically retracting thehead and tube from the bottle at the conclusion of the dwell part of thecycle.
 5. The apparatus of claim 4 including:(a) a low pressure watersupply circuit including automatic valve means acting to connect asource of low pressure water with said tube during the first part of thedwell and including a check valve to prevent backflow of water in saidcircuit, and (b) a high pressure water circuit including automatic valvemeans for connecting a high pressure source of water to said annularspace during a later part of the dwell.
 6. Apparatus for rapidly fillinga container with a low pressure liquid and then supplying a highpressure liquid to the container to pressure test the container, saidapparatus comprising:(a) a sealing and liquid supply head movablebetween a retracted position separated from a bottle at a test stationto allow movement of a bottle into and out of such station and a secondposition in sealing engagement with the container at the test stationfor filling and for application of hydraulic pressure (b) a tube carriedby and projecting from the head to penetrate the container when the headis in its second, sealing position to supply a low pressure liquid tothe container, said tube and head forming .[.an annular.]. .Iadd.a.Iaddend.passage between the tube and the head for passage of highpressure liquid (c) a low pressure circuit for supplying a low pressureliquid through the tube to the container to fill the container rapidly(d) means for venting displaced air during the filling step through said.[.annular.]. passage (e) a high pressure supply circuit for supplyinghigh pressure liquid to the filled container through said .[.annular.].passage to pressure test the container and (f) valve means in the highpressure circuit adapted to function as an air bleed for displaced airduring the filling operation and to allow introduction of liquid underpressure during the high pressure testing operation.
 7. Apparatus forpressure testing containers comprising:(a) a container support at a teststation for supporting a container with its opening uppermost (b) a testhead mounted for movement between an up position separated from acontainer at the test station and a down position in sealing engagementwith the container, said test head including a tube for passage of lowpressure water, said tube projecting from the lower end of the test headand into the container when the test head is in its down position, saidhead and tube providing also .[.an annular.]. .Iadd.a .Iaddend.passagefor high pressure water (c) means for moving said head automaticallythrough a repetitious cycle including a downward movement into sealingengagement with a container, a dwell following such downward movementduring filling and pressure testing and retraction after completion oftesting (d) low pressure supply means and high pressure supply meansfor, respectively, filing the container through the tube with lowpressure water and then applying high pressure water to the filledcontainer to pressure test it, said high pressure supply means actingalso to vent air displaced during the filling part of the dwell (e) andmeans for moving the test head between its up and down positions, saidmeans including an air cylinder, a piston reciprocable within thecylinder and a rod connecting the piston to the test head, a highpressure air supply to the cylinder above the piston to cause itsdownward movement and sealing engagement with the container and a lowpressure air supply to the cylinder beneath the piston operable when thehigh pressure air supply is terminated to move the piston and with thetest head upwardly to their up positions. .[.8. In bottle testingapparatus of the internal hydraulic pressure type wherein a bottle isfirst filled with water at low pressure, air displaced during filling isvented and then high pressure water is applied to the filled bottle, theimprovement which comprises: (a) a sealing head for sealing aginst thecrown of the bottle during filling and testing, (b) a central ductprojecting from the sealing head and penetrating the bottle duringfilling and testing, said duct and head forming a space therebetween,and (c) pressure sensing means carried by the head and exposed topressure in said space to sense the maintenance of pressure in thebottle and to sense loss of pressure due to failure or a leak..]. .[.9.The improvement of claim 8 wherein said pressure sensing means includesa rod exposed to pressure in said space and reciprocable within apassage and means acting on the rod at low pressure to urge the rod to afirst position upon failure of pressure and yielding to pressure when abottle is sound..]. Bottle testing apparatus of the type wherein thebottle to be tested is first filled with low pressure water and thenhigh pressure water is applied to the filled bottle, comprising:(a) atest head having a first passage for flow of low pressure water into thebottle while the crown of the bottle is sealed by said head, and asecond passage for outflow of displaced air during filling and for inputof high pressure water during testing, (b) a low pressure water supplyand means connecting said first passage with said supply during afilling step, said second passage serving to vent air that is displacedduring filling, (c) a high pressure water supply and means connectingsaid second passage to such supply when the bottle was been filled, and(d) means for establishing communication of said low pressure supplywith said first passage during the filling step, and (e) means forclosing communication of said low pressure supply to said first passageand for establishing communication of said high pressure water supply tosaid second passage during the pressure testing step. .[. . In a bottletesting wherein a bottle is sealed by a sealing chuck, is filled withwater at low pressure and is then submitted to high pressure water fortesting, the improvement which comprises a sealing chuck having passagesfor inflow of low pressure water, outflow of displaced air and inflow ofhigh pressure water, said chuck having a tapered inner sealing surfacewhich is tangent to the exterior of the crown of the bottle during thefilling and pressure testing steps..].
 12. Bottle testing apparatuscomprising a filling and testing station including a bottom support fora bottle, a bottle filling and pressure applying unit which isreciprocable between an up position clearing a bottle at such stationand a down position for sealing engagement with the top of a bottle atsuch station, said unit including a first passage for inflow of water atlow pressure during filling of the bottle and a second passage foroutflow of displaced air during such filling and for inflow of highpressure water for pressure testing, a source of water under lowpressure, a source of water under high pressure, means including a checkvalve for supplying low pressure water to said first passage duringfilling of the bottle, said check valve acting to prevent reverse flowof water through said first passage, means connecting said high pressuresource of water to said second passage including a valve serving duringfilling of a bottle with low pressure water to vent air displaced fromthe bottle during filling and acting, when high pressure water isapplied to said second passage, to prevent outflow of high pressurewater. .[.13. A method of testing bottles comprising:(a) sealing the topof a bottle resting on a bottom support and filling the bottle withwater at low pressure, meanwhile venting displaced air from the bottlewithout breaking the seal (b) then applying high pressure water to thewater in the filled container while the bottle is clamped between thetop seal and the bottom support (c) holding the filled bottle withapplied pressure for a short period of time and (d) sensing loss ofpressure due to failure of the bottle or leakage at the top of thebottle at the point of sealing..]. .Iadd.
 14. In bottle testingapparatus of the internal hydraulic pressure type wherein a bottle isfirst filled with water at low pressure, air displaced during filling isvented and then high pressure water is applied to the filled bottle, theimprovement which comprises: (a) a sealing head for sealing against thecrown of the bottle during filling and testing, (b) a central ductprojecting from the sealing head and penetrating the bottle duringfilling and testing, said duct and head forming a space therebetween,and (c) pressure sensing means carried by the head and exposed topressure in said space to sense the maintenance of pressure in thebottle and to sense loss of pressure due to failure or a leak, saidpressure sensing means including a rod exposed to pressure in said spaceand reciprocable within a passage and means acting on the rod at lowpressure to urge the rod to a first position upon failure of pressureand yielding to pressure when a bottle is sound. .Iaddend.